The dance someone does when they unexpectedly fall into a cold river.
"Did you see that turtle in the river?"
"No."
"Hang on and i'll try to get him to move..."
(Slides, and SPLASH...Arms flaling, legs kicking in a most disturbing manner, look on face priceless)
"Ooooo! Aaaah! Coooold!...Hey, where's the turtle?"
"Um, I don't think he liked your 'River Dance'!"